/*
 * SPDX-FileCopyrightText: 2010-2026 Sébastien Helleu <flashcode@flashtux.org>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

/* Implementation of hashtable */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>

#include "weechat.h"
#include "core-hashtable.h"
#include "core-infolist.h"
#include "core-list.h"
#include "core-log.h"
#include "core-string.h"
#include "core-utf8.h"
#include "../plugins/plugin.h"


/*
 * Grow (double) the internal array when the average chain length
 * (items_count / size) exceeds this value.
 */
#define HASHTABLE_LOAD_FACTOR_MAX 2

/*
 * Shrink (halve) the internal array when the average chain length
 * (items_count / size) falls below 1 / HASHTABLE_LOAD_FACTOR_MIN.
 *
 * Kept well below 1 / HASHTABLE_LOAD_FACTOR_MAX (ie 1/2) on purpose: this
 * leaves a hysteresis gap around the grow threshold so that adding/removing
 * a single item near any boundary can never flip the table back and forth
 * between growing and shrinking.
 */
#define HASHTABLE_LOAD_FACTOR_MIN 4

/*
 * Never shrink the internal array below this many buckets: avoids
 * repeatedly rehashing an already-small table for a negligible memory gain.
 */
#define HASHTABLE_MIN_SIZE 8


char *hashtable_type_string[HASHTABLE_NUM_TYPES] =
{ WEECHAT_HASHTABLE_INTEGER,
  WEECHAT_HASHTABLE_STRING,
  WEECHAT_HASHTABLE_POINTER,
  WEECHAT_HASHTABLE_BUFFER,
  WEECHAT_HASHTABLE_TIME,
  WEECHAT_HASHTABLE_LONGLONG };


/*
 * Search for a hashtable type.
 *
 * Return index of type in enum t_hashtable_type, -1 if type is not found.
 */

int
hashtable_get_type (const char *type)
{
    int i;

    if (!type)
        return -1;

    for (i = 0; i < HASHTABLE_NUM_TYPES; i++)
    {
        if (strcmp (hashtable_type_string[i], type) == 0)
            return i;
    }

    /* Type not found */
    return -1;
}

/*
 * Hash a string using a variant of djb2 hash.
 *
 * Return the hash of the string.
 */

unsigned long long
hashtable_hash_key_djb2 (const char *string)
{
    uint64_t hash;
    const char *ptr_string;

    hash = 5381;
    if (string)
    {
        for (ptr_string = string; ptr_string[0]; ptr_string++)
        {
            hash ^= (hash << 5) + (hash >> 2) + (int)(ptr_string[0]);
        }
    }

    return hash;
}

/*
 * Hash a key (default callback).
 *
 * Return the hash of the key, depending on the type.
 */

unsigned long long
hashtable_hash_key_default_cb (struct t_hashtable *hashtable, const void *key)
{
    switch (hashtable->type_keys)
    {
        case HASHTABLE_INTEGER:
            if (key)
                return (unsigned long long)(*((int *)key));
            break;
        case HASHTABLE_STRING:
            if (key)
                return hashtable_hash_key_djb2 ((const char *)key);
            break;
        case HASHTABLE_POINTER:
            return (unsigned long long)((unsigned long)((void *)key));
        case HASHTABLE_BUFFER:
            break;
        case HASHTABLE_TIME:
            if (key)
                return (unsigned long long)(*((time_t *)key));
            break;
        case HASHTABLE_LONGLONG:
            if (key)
                return (unsigned long long)(*((long long *)key));
            break;
        case HASHTABLE_NUM_TYPES:
            break;
    }
    return 0ULL;
}

/*
 * Compare two keys (default callback).
 *
 * Return:
 *   < 0: key1 < key2
 *     0: key1 == key2
 *   > 0: key1 > key2
 */

int
hashtable_keycmp_default_cb (struct t_hashtable *hashtable,
                             const void *key1, const void *key2)
{
    int rc;

    /* Make C compiler happy. */
    (void) hashtable;

    if (!key1 && !key2)
        return 0;
    if (!key1 && key2)
        return -1;
    if (key1 && !key2)
        return 1;

    rc = 0;

    switch (hashtable->type_keys)
    {
        case HASHTABLE_INTEGER:
            if (*((int *)key1) < *((int *)key2))
                rc = -1;
            else if (*((int *)key1) > *((int *)key2))
                rc = 1;
            break;
        case HASHTABLE_STRING:
            rc = strcmp ((const char *)key1, (const char *)key2);
            break;
        case HASHTABLE_POINTER:
            if (key1 < key2)
                rc = -1;
            else if (key1 > key2)
                rc = 1;
            break;
        case HASHTABLE_BUFFER:
            break;
        case HASHTABLE_TIME:
            if (*((time_t *)key1) < *((time_t *)key2))
                rc = -1;
            else if (*((time_t *)key1) > *((time_t *)key2))
                rc = 1;
            break;
        case HASHTABLE_LONGLONG:
            if (*((long long *)key1) < *((long long *)key2))
                rc = -1;
            else if (*((long long *)key1) > *((long long *)key2))
                rc = 1;
            break;
        case HASHTABLE_NUM_TYPES:
            break;
    }

    return rc;
}

/*
 * Create a new hashtable.
 *
 * The size is NOT a limit for number of items in hashtable, and it is only
 * an *initial* size: it is the size of the internal array used to store
 * hashed keys, and the array is grown or shrunk automatically (see
 * hashtable_rehash) as items are added or removed, to keep the average
 * length of the linked lists low regardless of how many items end up in
 * the hashtable, down to a minimum of HASHTABLE_MIN_SIZE buckets.
 *
 * Return pointer to new hashtable, NULL if error.
 */

struct t_hashtable *
hashtable_new (int size,
               const char *type_keys, const char *type_values,
               t_hashtable_hash_key *callback_hash_key,
               t_hashtable_keycmp *callback_keycmp)
{
    struct t_hashtable *new_hashtable;
    int i, type_keys_int, type_values_int;

    if (size <= 0)
        return NULL;

    type_keys_int = hashtable_get_type (type_keys);
    if (type_keys_int < 0)
        return NULL;
    type_values_int = hashtable_get_type (type_values);
    if (type_values_int < 0)
        return NULL;

    /* The two callbacks are mandatory if type of keys is "buffer". */
    if ((type_keys_int == HASHTABLE_BUFFER) && (!callback_hash_key || !callback_keycmp))
        return NULL;

    new_hashtable = malloc (sizeof (*new_hashtable));
    if (new_hashtable)
    {
        new_hashtable->size = size;
        new_hashtable->type_keys = type_keys_int;
        new_hashtable->type_values = type_values_int;
        new_hashtable->htable = malloc (size * sizeof (*(new_hashtable->htable)));
        new_hashtable->keys_values = NULL;
        if (!new_hashtable->htable)
        {
            free (new_hashtable);
            return NULL;
        }
        for (i = 0; i < size; i++)
        {
            new_hashtable->htable[i] = NULL;
        }
        new_hashtable->items_count = 0;
        new_hashtable->oldest_item = NULL;
        new_hashtable->newest_item = NULL;

        new_hashtable->callback_hash_key = (callback_hash_key) ?
            callback_hash_key : &hashtable_hash_key_default_cb;
        new_hashtable->callback_keycmp = (callback_keycmp) ?
            callback_keycmp : &hashtable_keycmp_default_cb;

        new_hashtable->callback_free_key = NULL;
        new_hashtable->callback_free_value = NULL;
    }
    return new_hashtable;
}

/*
 * Allocate space for a key or value.
 */

void
hashtable_alloc_type (enum t_hashtable_type type,
                      const void *value, int size_value,
                      void **pointer, int *size)
{
    switch (type)
    {
        case HASHTABLE_INTEGER:
            if (value)
            {
                *pointer = malloc (sizeof (int));
                if (*pointer)
                    *((int *)(*pointer)) = *((int *)value);
            }
            else
                *pointer = NULL;
            *size = (*pointer) ? sizeof (int) : 0;
            break;
        case HASHTABLE_STRING:
            *pointer = (value) ? strdup ((const char *)value) : NULL;
            *size = (*pointer) ? strlen (*pointer) + 1 : 0;
            break;
        case HASHTABLE_POINTER:
            *pointer = (void *)value;
            *size = sizeof (void *);
            break;
        case HASHTABLE_BUFFER:
            if (value && (size_value > 0))
            {
                *pointer = malloc (size_value);
                if (*pointer)
                    memcpy (*pointer, value, size_value);
            }
            else
                *pointer = NULL;
            *size = (*pointer) ? size_value : 0;
            break;
        case HASHTABLE_TIME:
            if (value)
            {
                *pointer = malloc (sizeof (time_t));
                if (*pointer)
                    *((time_t *)(*pointer)) = *((time_t *)value);
            }
            else
                *pointer = NULL;
            *size = (*pointer) ? sizeof (time_t) : 0;
            break;
        case HASHTABLE_LONGLONG:
            if (value)
            {
                *pointer = malloc (sizeof (long long));
                if (*pointer)
                    *((long long *)(*pointer)) = *((long long *)value);
            }
            else
                *pointer = NULL;
            *size = (*pointer) ? sizeof (long long) : 0;
            break;
        case HASHTABLE_NUM_TYPES:
            break;
    }
}

/*
 * Free space used by a key.
 */

void
hashtable_free_key (struct t_hashtable *hashtable,
                    struct t_hashtable_item *item)
{
    if (hashtable->callback_free_key)
    {
        (void) (hashtable->callback_free_key) (hashtable,
                                               item->key);
    }
    else
    {
        switch (hashtable->type_keys)
        {
            case HASHTABLE_INTEGER:
            case HASHTABLE_STRING:
            case HASHTABLE_BUFFER:
            case HASHTABLE_TIME:
            case HASHTABLE_LONGLONG:
                free (item->key);
                break;
            case HASHTABLE_POINTER:
                break;
            case HASHTABLE_NUM_TYPES:
                break;
        }
    }
}

/*
 * Free space used by a value.
 */

void
hashtable_free_value (struct t_hashtable *hashtable,
                      struct t_hashtable_item *item)
{
    if (hashtable->callback_free_value)
    {
        (void) (hashtable->callback_free_value) (hashtable,
                                                 item->key,
                                                 item->value);
    }
    else
    {
        switch (hashtable->type_values)
        {
            case HASHTABLE_INTEGER:
            case HASHTABLE_STRING:
            case HASHTABLE_BUFFER:
            case HASHTABLE_TIME:
            case HASHTABLE_LONGLONG:
                free (item->value);
                break;
            case HASHTABLE_POINTER:
                break;
            case HASHTABLE_NUM_TYPES:
                break;
        }
    }
}

/*
 * Rehash a hashtable: allocate a new internal array of "new_size" buckets
 * and move all existing items into it.
 *
 * This keeps the average linked-list length in each bucket low as items are
 * added or removed, instead of it growing linearly with items_count for a
 * fixed-size array.
 *
 * Each item is reinserted at its sorted position in its new bucket (not
 * simply appended), to preserve the per-bucket sorted-by-key invariant that
 * hashtable_get_item and hashtable_set_with_size rely on for their
 * early-exit comparison.
 */

void
hashtable_rehash (struct t_hashtable *hashtable, int new_size)
{
    struct t_hashtable_item **new_htable, *ptr_item, *ptr_next_item;
    struct t_hashtable_item *ptr_bucket_item, *pos_item;
    unsigned long long hash;
    int i;

    new_htable = malloc (new_size * sizeof (*new_htable));
    if (!new_htable)
        return;

    for (i = 0; i < new_size; i++)
    {
        new_htable[i] = NULL;
    }

    for (i = 0; i < hashtable->size; i++)
    {
        ptr_item = hashtable->htable[i];
        while (ptr_item)
        {
            ptr_next_item = ptr_item->next_item;

            hash = hashtable->callback_hash_key (hashtable, ptr_item->key) % new_size;

            /* Find sorted position for item in its new bucket. */
            pos_item = NULL;
            for (ptr_bucket_item = new_htable[hash];
                 ptr_bucket_item
                     && ((int)(hashtable->callback_keycmp) (hashtable, ptr_item->key, ptr_bucket_item->key) > 0);
                 ptr_bucket_item = ptr_bucket_item->next_item)
            {
                pos_item = ptr_bucket_item;
            }

            ptr_item->prev_item = pos_item;
            ptr_item->next_item = (pos_item) ? pos_item->next_item : new_htable[hash];
            if (ptr_item->next_item)
                (ptr_item->next_item)->prev_item = ptr_item;
            if (pos_item)
                pos_item->next_item = ptr_item;
            else
                new_htable[hash] = ptr_item;

            ptr_item = ptr_next_item;
        }
    }

    free (hashtable->htable);
    hashtable->htable = new_htable;
    hashtable->size = new_size;
}

/*
 * Set value for a key in hashtable.
 *
 * The size arguments are used only for type "buffer".
 *
 * Return pointer to item created/updated, NULL if error.
 */

struct t_hashtable_item *
hashtable_set_with_size (struct t_hashtable *hashtable,
                         const void *key, int key_size,
                         const void *value, int value_size)
{
    unsigned long long hash;
    struct t_hashtable_item *ptr_item, *pos_item, *new_item;

    if (!hashtable
        || ((hashtable->type_keys == HASHTABLE_BUFFER) && (key_size <= 0))
        || ((hashtable->type_values == HASHTABLE_BUFFER) && (value_size <= 0)))
    {
        return NULL;
    }

    /* Search position for item in hashtable. */
    hash = hashtable->callback_hash_key (hashtable, key) % hashtable->size;
    pos_item = NULL;
    for (ptr_item = hashtable->htable[hash];
         ptr_item
             && ((int)(hashtable->callback_keycmp) (hashtable, key, ptr_item->key) > 0);
         ptr_item = ptr_item->next_item)
    {
        pos_item = ptr_item;
    }

    /* Replace value if item is already in hashtable. */
    if (ptr_item && (hashtable->callback_keycmp (hashtable, key, ptr_item->key) == 0))
    {
        hashtable_free_value (hashtable, ptr_item);
        hashtable_alloc_type (hashtable->type_values,
                              value, value_size,
                              &ptr_item->value, &ptr_item->value_size);
        return ptr_item;
    }

    /* Create new item. */
    new_item = malloc (sizeof (*new_item));
    if (!new_item)
        return NULL;

    /* Set key and value. */
    hashtable_alloc_type (hashtable->type_keys,
                          key, key_size,
                          &new_item->key, &new_item->key_size);
    hashtable_alloc_type (hashtable->type_values,
                          value, value_size,
                          &new_item->value, &new_item->value_size);

    /* Add item. */
    if (pos_item)
    {
        /* Insert item after position found. */
        new_item->prev_item = pos_item;
        new_item->next_item = pos_item->next_item;
        if (pos_item->next_item)
            (pos_item->next_item)->prev_item = new_item;
        pos_item->next_item = new_item;
    }
    else
    {
        /* Insert item at beginning of list. */
        new_item->prev_item = NULL;
        new_item->next_item = hashtable->htable[hash];
        if (hashtable->htable[hash])
            (hashtable->htable[hash])->prev_item = new_item;
        hashtable->htable[hash] = new_item;
    }

    /* Keep items ordered by date of creation. */
    if (hashtable->newest_item)
        (hashtable->newest_item)->next_created_item = new_item;
    else
        hashtable->oldest_item = new_item;
    new_item->prev_created_item = hashtable->newest_item;
    new_item->next_created_item = NULL;
    hashtable->newest_item = new_item;

    hashtable->items_count++;

    /* Grow the table if the average chain length is too high. */
    if (hashtable->items_count > hashtable->size * HASHTABLE_LOAD_FACTOR_MAX)
        hashtable_rehash (hashtable, hashtable->size * 2);

    return new_item;
}

/*
 * Set value for a key in hashtable.
 *
 * Note: this function can be called *only* if key AND value are *not* of type
 * "buffer".
 *
 * Return pointer to item created/updated, NULL if error.
 */

struct t_hashtable_item *
hashtable_set (struct t_hashtable *hashtable,
               const void *key, const void *value)
{
    return hashtable_set_with_size (hashtable, key, 0, value, 0);
}

/*
 * Search for an item in hashtable.
 *
 * If hash is non NULL, then set it with hash value of key (even if key is
 * not found).
 */

struct t_hashtable_item *
hashtable_get_item (struct t_hashtable *hashtable, const void *key,
                    unsigned long long *hash)
{
    unsigned long long key_hash;
    struct t_hashtable_item *ptr_item;

    if (!hashtable)
        return NULL;

    key_hash = hashtable->callback_hash_key (hashtable, key) % hashtable->size;
    if (hash)
        *hash = key_hash;
    for (ptr_item = hashtable->htable[key_hash];
         ptr_item && hashtable->callback_keycmp (hashtable, key, ptr_item->key) > 0;
         ptr_item = ptr_item->next_item)
    {
    }

    if (ptr_item
        && (hashtable->callback_keycmp (hashtable, key, ptr_item->key) == 0))
    {
        return ptr_item;
    }

    return NULL;
}

/*
 * Get value for a key in hashtable.
 *
 * Return pointer to value for key, NULL if key is not found.
 */

void *
hashtable_get (struct t_hashtable *hashtable, const void *key)
{
    struct t_hashtable_item *ptr_item;

    ptr_item = hashtable_get_item (hashtable, key, NULL);

    return (ptr_item) ? ptr_item->value : NULL;
}

/*
 * Check if a key exists in the hashtable.
 *
 * Return:
 *   1: key exists
 *   0: key does not exist
 */

int
hashtable_has_key (struct t_hashtable *hashtable, const void *key)
{
    return (hashtable_get_item (hashtable, key, NULL) != NULL) ? 1 : 0;
}

/*
 * Convert a value (from any type) to a string.
 *
 * Return pointer to a static buffer (for type string, return pointer to
 * string itself), which must be used immediately, it is overwritten by
 * subsequent calls to this function.
 */

const char *
hashtable_to_string (enum t_hashtable_type type, const void *value)
{
    static char str_value[128];

    switch (type)
    {
        case HASHTABLE_INTEGER:
            snprintf (str_value, sizeof (str_value), "%d", *((int *)value));
            return str_value;
        case HASHTABLE_STRING:
            return (const char *)value;
        case HASHTABLE_POINTER:
        case HASHTABLE_BUFFER:
            snprintf (str_value, sizeof (str_value), "0x%lx",
                      (unsigned long)value);
            return str_value;
        case HASHTABLE_TIME:
            snprintf (str_value, sizeof (str_value),
                      "%lld", (long long)(*((time_t *)value)));
            return str_value;
        case HASHTABLE_LONGLONG:
            snprintf (str_value, sizeof (str_value),
                      "%lld", *((long long *)value));
            return str_value;
        case HASHTABLE_NUM_TYPES:
            break;
    }

    return NULL;
}

/*
 * Call a function on all hashtable entries.
 */

void
hashtable_map (struct t_hashtable *hashtable,
               t_hashtable_map *callback_map,
               void *callback_map_data)
{
    struct t_hashtable_item *ptr_item, *ptr_next_created_item;

    if (!hashtable)
        return;

    ptr_item = hashtable->oldest_item;
    while (ptr_item)
    {
        ptr_next_created_item = ptr_item->next_created_item;

        (void) (callback_map) (callback_map_data,
                               hashtable,
                               ptr_item->key,
                               ptr_item->value);

        ptr_item = ptr_next_created_item;
    }
}

/*
 * Call a function on all hashtable entries (sends keys and values as strings).
 */

void
hashtable_map_string (struct t_hashtable *hashtable,
                      t_hashtable_map_string *callback_map,
                      void *callback_map_data)
{
    struct t_hashtable_item *ptr_item, *ptr_next_created_item;
    const char *str_key, *str_value;
    char *key, *value;

    if (!hashtable)
        return;

    ptr_item = hashtable->oldest_item;
    while (ptr_item)
    {
        ptr_next_created_item = ptr_item->next_created_item;

        str_key = hashtable_to_string (hashtable->type_keys,
                                       ptr_item->key);
        key = (str_key) ? strdup (str_key) : NULL;

        str_value = hashtable_to_string (hashtable->type_values,
                                         ptr_item->value);
        value = (str_value) ? strdup (str_value) : NULL;

        (void) (callback_map) (callback_map_data,
                               hashtable,
                               key,
                               value);

        free (key);
        free (value);

        ptr_item = ptr_next_created_item;
    }
}

/*
 * Duplicate key/value in another hashtable (callback called for each variable
 * in hashtable).
 */

void
hashtable_duplicate_map_cb (void *data,
                            struct t_hashtable *hashtable,
                            const void *key, const void *value)
{
    struct t_hashtable *hashtable2;

    /* Make C compiler happy. */
    (void) hashtable;

    hashtable2 = (struct t_hashtable *)data;
    if (hashtable2)
        hashtable_set (hashtable2, key, value);
}

/*
 * Duplicate a hashtable.
 *
 * Return pointer to new hashtable, NULL if error.
 */

struct t_hashtable *
hashtable_dup (struct t_hashtable *hashtable)
{
    struct t_hashtable *new_hashtable;

    if (!hashtable)
        return NULL;

    new_hashtable = hashtable_new (hashtable->size,
                                   hashtable_type_string[hashtable->type_keys],
                                   hashtable_type_string[hashtable->type_values],
                                   hashtable->callback_hash_key,
                                   hashtable->callback_keycmp);
    if (new_hashtable)
    {
        new_hashtable->callback_free_key = hashtable->callback_free_key;
        new_hashtable->callback_free_value = hashtable->callback_free_value;
        hashtable_map (hashtable,
                       &hashtable_duplicate_map_cb,
                       new_hashtable);
    }

    return new_hashtable;
}

/*
 * Build sorted list of keys (callback called for each variable in hashtable).
 */

void
hashtable_get_list_keys_map_cb (void *data,
                                struct t_hashtable *hashtable,
                                const void *key, const void *value)
{
    struct t_weelist *list;

    /* Make C compiler happy. */
    (void) hashtable;
    (void) value;

    list = (struct t_weelist *)data;

    weelist_add (list, hashtable_to_string (hashtable->type_keys, key),
                 WEECHAT_LIST_POS_SORT, NULL);
}

/*
 * Get list with sorted keys of hashtable.
 *
 * Note: list must be freed after use.
 */

struct t_weelist *
hashtable_get_list_keys (struct t_hashtable *hashtable)
{
    struct t_weelist *weelist;

    if (!hashtable)
        return NULL;

    weelist = weelist_new ();
    if (weelist)
        hashtable_map (hashtable, &hashtable_get_list_keys_map_cb, weelist);
    return weelist;
}

/*
 * Get a hashtable property as integer.
 */

int
hashtable_get_integer (struct t_hashtable *hashtable, const char *property)
{
    if (!hashtable || !property)
        return 0;

    if (strcmp (property, "size") == 0)
        return hashtable->size;
    else if (strcmp (property, "items_count") == 0)
        return hashtable->items_count;

    return 0;
}

/*
 * Compute length of all keys (callback called for each variable in hashtable).
 */

void
hashtable_compute_length_keys_cb (void *data,
                                  struct t_hashtable *hashtable,
                                  const void *key, const void *value)
{
    const char *str_key;
    int *length;

    /* Make C compiler happy. */
    (void) value;

    length = (int *)data;

    str_key = hashtable_to_string (hashtable->type_keys, key);
    if (str_key)
        *length += strlen (str_key) + 1;
}

/*
 * Compute length of all values (callback called for each variable in
 * hashtable).
 */

void
hashtable_compute_length_values_cb (void *data,
                                    struct t_hashtable *hashtable,
                                    const void *key, const void *value)
{
    const char *str_value;
    int *length;

    /* Make C compiler happy. */
    (void) key;

    length = (int *)data;

    if (value)
    {
        str_value = hashtable_to_string (hashtable->type_values, value);
        if (str_value)
            *length += strlen (str_value) + 1;
    }
    else
    {
        *length += strlen ("(null)") + 1;
    }
}

/*
 * Compute length of all keys + values (callback called for each variable in
 * hashtable).
 */

void
hashtable_compute_length_keys_values_cb (void *data,
                                         struct t_hashtable *hashtable,
                                         const void *key, const void *value)
{
    hashtable_compute_length_keys_cb (data, hashtable, key, value);
    hashtable_compute_length_values_cb (data, hashtable, key, value);
}

/*
 * Build a string with all keys (callback called for each variable in
 * hashtable).
 */

void
hashtable_build_string_keys_cb (void *data,
                                struct t_hashtable *hashtable,
                                const void *key, const void *value)
{
    const char *str_key;
    char *str;

    /* Make C compiler happy. */
    (void) value;

    str = (char *)data;

    if (str[0])
        strcat (str, ",");

    str_key = hashtable_to_string (hashtable->type_keys, key);
    if (str_key)
        strcat (str, str_key);
}

/*
 * Build a string with all values (callback called for each variable in
 * hashtable).
 */

void
hashtable_build_string_values_cb (void *data,
                                  struct t_hashtable *hashtable,
                                  const void *key, const void *value)
{
    const char *str_value;
    char *str;

    /* Make C compiler happy. */
    (void) key;

    str = (char *)data;

    if (str[0])
        strcat (str, ",");

    if (value)
    {
        str_value = hashtable_to_string (hashtable->type_values, value);
        if (str_value)
            strcat (str, str_value);
    }
    else
    {
        strcat (str, "(null)");
    }
}

/*
 * Build a string with all keys + values (callback called for each variable in
 * hashtable).
 */

void
hashtable_build_string_keys_values_cb (void *data,
                                       struct t_hashtable *hashtable,
                                       const void *key, const void *value)
{
    const char *str_key, *str_value;
    char *str;

    str = (char *)data;

    if (str[0])
        strcat (str, ",");

    str_key = hashtable_to_string (hashtable->type_keys, key);
    if (str_key)
        strcat (str, str_key);

    strcat (str, ":");

    if (value)
    {
        str_value = hashtable_to_string (hashtable->type_values, value);
        if (str_value)
            strcat (str, str_value);
    }
    else
    {
        strcat (str, "(null)");
    }
}

/*
 * Get keys and/or values of hashtable as string.
 *
 * Return a string with one of these formats:
 *   if keys == 1 and values == 0: "key1,key2,key3"
 *   if keys == 0 and values == 1: "value1,value2,value3"
 *   if keys == 1 and values == 1: "key1:value1,key2:value2,key3:value3"
 */

const char *
hashtable_get_keys_values (struct t_hashtable *hashtable,
                           int keys, int sort_keys, int values)
{
    int length;
    struct t_weelist *list_keys;
    struct t_weelist_item *ptr_item;

    if (hashtable->keys_values)
    {
        free (hashtable->keys_values);
        hashtable->keys_values = NULL;
    }

    /* First compute length of string. */
    length = 0;
    hashtable_map (hashtable,
                   (keys && values) ? &hashtable_compute_length_keys_values_cb :
                   ((keys) ? &hashtable_compute_length_keys_cb :
                    &hashtable_compute_length_values_cb),
                   &length);
    if (length == 0)
        return hashtable->keys_values;

    /* Build string. */
    hashtable->keys_values = malloc (length + 1);
    if (!hashtable->keys_values)
        return NULL;
    hashtable->keys_values[0] = '\0';
    if (keys && sort_keys)
    {
        list_keys = hashtable_get_list_keys (hashtable);
        if (list_keys)
        {
            for (ptr_item = list_keys->items; ptr_item;
                 ptr_item = ptr_item->next_item)
            {
                if (values)
                {
                    hashtable_build_string_keys_values_cb (hashtable->keys_values,
                                                           hashtable,
                                                           ptr_item->data,
                                                           hashtable_get (hashtable,
                                                                          ptr_item->data));
                }
                else
                {
                    hashtable_build_string_keys_cb (hashtable->keys_values,
                                                    hashtable,
                                                    ptr_item->data,
                                                    NULL);
                }
            }
            weelist_free (list_keys);
        }
    }
    else
    {
        hashtable_map (hashtable,
                       (keys && values) ? &hashtable_build_string_keys_values_cb :
                       ((keys) ? &hashtable_build_string_keys_cb :
                        &hashtable_build_string_values_cb),
                       hashtable->keys_values);
    }

    return hashtable->keys_values;
}

/*
 * Get a hashtable property as string.
 */

const char *
hashtable_get_string (struct t_hashtable *hashtable, const char *property)
{
    if (!hashtable || !property)
        return NULL;

    if (strcmp (property, "type_keys") == 0)
        return hashtable_type_string[hashtable->type_keys];
    else if (strcmp (property, "type_values") == 0)
        return hashtable_type_string[hashtable->type_values];
    else if (strcmp (property, "keys") == 0)
        return hashtable_get_keys_values (hashtable, 1, 0, 0);
    else if (strcmp (property, "keys_sorted") == 0)
        return hashtable_get_keys_values (hashtable, 1, 1, 0);
    else if (strcmp (property, "values") == 0)
        return hashtable_get_keys_values (hashtable, 0, 0, 1);
    else if (strcmp (property, "keys_values") == 0)
        return hashtable_get_keys_values (hashtable, 1, 0, 1);
    else if (strcmp (property, "keys_values_sorted") == 0)
        return hashtable_get_keys_values (hashtable, 1, 1, 1);

    return NULL;
}

/*
 * Set a hashtable property (pointer).
 */

void
hashtable_set_pointer (struct t_hashtable *hashtable, const char *property,
                       void *pointer)
{
    if (!hashtable || !property)
        return;

    if (strcmp (property, "callback_free_key") == 0)
        hashtable->callback_free_key = pointer;
    else if (strcmp (property, "callback_free_value") == 0)
        hashtable->callback_free_value = pointer;
}

/*
 * Add hashtable keys and values in an infolist.
 *
 * Return:
 *   1: OK
 *   0: error
 */

int
hashtable_add_to_infolist (struct t_hashtable *hashtable,
                           struct t_infolist_item *infolist_item,
                           const char *prefix)
{
    int item_number;
    struct t_hashtable_item *ptr_item;
    char option_name[128], value[128];

    if (!hashtable || !infolist_item || !prefix)
        return 0;

    item_number = 0;
    ptr_item = hashtable->oldest_item;
    while (ptr_item)
    {
        snprintf (option_name, sizeof (option_name),
                  "%s_name_%05d", prefix, item_number);
        if (!infolist_new_var_string (infolist_item, option_name,
                                      hashtable_to_string (hashtable->type_keys,
                                                           ptr_item->key)))
            return 0;
        snprintf (option_name, sizeof (option_name),
                  "%s_value_%05d", prefix, item_number);
        switch (hashtable->type_values)
        {
            case HASHTABLE_INTEGER:
                if (!infolist_new_var_integer (infolist_item, option_name,
                                               *((int *)ptr_item->value)))
                    return 0;
                break;
            case HASHTABLE_STRING:
                if (!infolist_new_var_string (infolist_item, option_name,
                                              (const char *)ptr_item->value))
                    return 0;
                break;
            case HASHTABLE_POINTER:
                if (!infolist_new_var_pointer (infolist_item, option_name,
                                               ptr_item->value))
                    return 0;
                break;
            case HASHTABLE_BUFFER:
                if (!infolist_new_var_buffer (infolist_item, option_name,
                                              ptr_item->value,
                                              ptr_item->value_size))
                    return 0;
                break;
            case HASHTABLE_TIME:
                if (!infolist_new_var_time (infolist_item, option_name,
                                            *((time_t *)ptr_item->value)))
                    return 0;
                break;
            case HASHTABLE_LONGLONG:
                snprintf (value, sizeof (value),
                          "%lld", *((long long *)ptr_item->value));
                if (!infolist_new_var_string (infolist_item, option_name, value))
                    return 0;
                break;
            case HASHTABLE_NUM_TYPES:
                break;
        }
        item_number++;
        ptr_item = ptr_item->next_created_item;
    }
    return 1;
}

/*
 * Add hashtable keys and values from an infolist.
 *
 * Return:
 *   1: OK
 *   0: error
 */

int
hashtable_add_from_infolist (struct t_hashtable *hashtable,
                             struct t_infolist *infolist,
                             const char *prefix)
{
    struct t_infolist_var *ptr_name, *ptr_value;
    char prefix_name[1024], option_value[1024];
    int prefix_length, prefix_length_utf8;

    if (!hashtable || !infolist || !infolist->ptr_item || !prefix)
        return 0;

    /* TODO: implement other key types */
    if (hashtable->type_keys != HASHTABLE_STRING)
        return 0;

    snprintf (prefix_name, sizeof (prefix_name), "%s_name_", prefix);
    prefix_length = strlen (prefix_name);
    prefix_length_utf8 = utf8_strlen (prefix_name);

    for (ptr_name = infolist->ptr_item->vars; ptr_name;
         ptr_name = ptr_name->next_var)
    {
        if (string_strncasecmp (ptr_name->name, prefix_name,
                                prefix_length_utf8) == 0)
        {
            snprintf (option_value, sizeof (option_value),
                      "%s_value_%s", prefix, ptr_name->name + prefix_length);

            ptr_value = infolist_search_var (infolist, option_value);
            if (ptr_value)
            {
                switch (hashtable->type_values)
                {
                    case HASHTABLE_INTEGER:
                        if (ptr_value->type != INFOLIST_INTEGER)
                            return 0;
                        break;
                    case HASHTABLE_STRING:
                        if (ptr_value->type != INFOLIST_STRING)
                            return 0;
                        break;
                    case HASHTABLE_POINTER:
                        if (ptr_value->type != INFOLIST_POINTER)
                            return 0;
                        break;
                    case HASHTABLE_BUFFER:
                        if (ptr_value->type != INFOLIST_BUFFER)
                            return 0;
                        break;
                    case HASHTABLE_TIME:
                        if (ptr_value->type != INFOLIST_TIME)
                            return 0;
                        break;
                    case HASHTABLE_LONGLONG:
                        if (ptr_value->type != INFOLIST_STRING)
                            return 0;
                        break;
                    case HASHTABLE_NUM_TYPES:
                        break;
                }
                if (hashtable->type_values == HASHTABLE_BUFFER)
                {
                    hashtable_set_with_size (hashtable,
                                             ptr_name->value,
                                             0,
                                             ptr_value->value,
                                             ptr_value->size);
                }
                else
                {
                    hashtable_set (hashtable,
                                   ptr_name->value,
                                   ptr_value->value);
                }
            }
        }
    }

    return 1;
}

/*
 * Remove an item from hashtable.
 *
 * Do not check/adjust the load factor: this is also called in a loop by
 * hashtable_remove_all, where shrinking mid-loop would invalidate the
 * loop's bucket indices (see hashtable_remove for the load factor check).
 */

void
hashtable_remove_item (struct t_hashtable *hashtable,
                       struct t_hashtable_item *item,
                       unsigned long long hash)
{
    if (!hashtable || !item)
        return;

    /* Free key and value. */
    hashtable_free_value (hashtable, item);
    hashtable_free_key (hashtable, item);

    /* Remove item from ordered list (by date of creation). */
    if (item->prev_created_item)
        (item->prev_created_item)->next_created_item = item->next_created_item;
    if (item->next_created_item)
        (item->next_created_item)->prev_created_item = item->prev_created_item;
    if (hashtable->oldest_item == item)
        hashtable->oldest_item = item->next_created_item;
    if (hashtable->newest_item == item)
        hashtable->newest_item = item->prev_created_item;

    /* Remove item from list. */
    if (item->prev_item)
        (item->prev_item)->next_item = item->next_item;
    if (item->next_item)
        (item->next_item)->prev_item = item->prev_item;
    if (hashtable->htable[hash] == item)
        hashtable->htable[hash] = item->next_item;

    free (item);

    hashtable->items_count--;
}

/*
 * Remove an item from hashtable (searches it with key).
 *
 * Also shrink the internal array (see hashtable_rehash) if the average
 * chain length drops too low after the removal.
 */

void
hashtable_remove (struct t_hashtable *hashtable, const void *key)
{
    struct t_hashtable_item *ptr_item;
    unsigned long long hash;
    int new_size;

    if (!hashtable || !key)
        return;

    ptr_item = hashtable_get_item (hashtable, key, &hash);
    if (ptr_item)
    {
        hashtable_remove_item (hashtable, ptr_item, hash);

        /* Shrink the table if the average chain length is too low. */
        if ((hashtable->size > HASHTABLE_MIN_SIZE)
            && (hashtable->items_count * HASHTABLE_LOAD_FACTOR_MIN < hashtable->size))
        {
            new_size = hashtable->size / 2;
            if (new_size < HASHTABLE_MIN_SIZE)
                new_size = HASHTABLE_MIN_SIZE;
            hashtable_rehash (hashtable, new_size);
        }
    }
}

/*
 * Remove all items from hashtable.
 *
 * Do not shrink the internal array: callers typically clear a hashtable
 * only to immediately refill it, so keeping the existing capacity avoids
 * forcing an unnecessary re-grow rehash right afterwards.
 */

void
hashtable_remove_all (struct t_hashtable *hashtable)
{
    int i;

    if (!hashtable)
        return;

    for (i = 0; i < hashtable->size; i++)
    {
        while (hashtable->htable[i])
        {
            hashtable_remove_item (hashtable, hashtable->htable[i], i);
        }
    }
}

/*
 * Free a hashtable: removes all items and frees hashtable.
 */

void
hashtable_free (struct t_hashtable *hashtable)
{
    if (!hashtable)
        return;

    hashtable_remove_all (hashtable);
    free (hashtable->htable);
    free (hashtable->keys_values);
    free (hashtable);
}

/*
 * Print hashtable in WeeChat log file (usually for crash dump).
 */

void
hashtable_print_log (struct t_hashtable *hashtable, const char *name)
{
    struct t_hashtable_item *ptr_item;
    int i;

    log_printf ("");
    log_printf ("[hashtable %s (addr:%p)]", name, hashtable);
    log_printf ("  size . . . . . . . . . : %d", hashtable->size);
    log_printf ("  htable . . . . . . . . : %p", hashtable->htable);
    log_printf ("  items_count. . . . . . : %d", hashtable->items_count);
    log_printf ("  oldest_item. . . . . . : %p", hashtable->oldest_item);
    log_printf ("  newest_item. . . . . . : %p", hashtable->newest_item);
    log_printf ("  type_keys. . . . . . . : %d (%s)",
                hashtable->type_keys,
                hashtable_type_string[hashtable->type_keys]);
    log_printf ("  type_values. . . . . . : %d (%s)",
                hashtable->type_values,
                hashtable_type_string[hashtable->type_values]);
    log_printf ("  callback_hash_key. . . : %p", hashtable->callback_hash_key);
    log_printf ("  callback_keycmp. . . . : %p", hashtable->callback_keycmp);
    log_printf ("  callback_free_key. . . : %p", hashtable->callback_free_key);
    log_printf ("  callback_free_value. . : %p", hashtable->callback_free_value);
    log_printf ("  keys_values. . . . . . : '%s'", hashtable->keys_values);

    for (i = 0; i < hashtable->size; i++)
    {
        log_printf ("  htable[%06d] . . . . : %p", i, hashtable->htable[i]);
        for (ptr_item = hashtable->htable[i]; ptr_item;
             ptr_item = ptr_item->next_item)
        {
            log_printf ("    [item %p]", hashtable->htable);
            switch (hashtable->type_keys)
            {
                case HASHTABLE_INTEGER:
                    log_printf ("      key (integer). . . : %d", *((int *)ptr_item->key));
                    break;
                case HASHTABLE_STRING:
                    log_printf ("      key (string) . . . : '%s'", (char *)ptr_item->key);
                    break;
                case HASHTABLE_POINTER:
                    log_printf ("      key (pointer). . . : %p", ptr_item->key);
                    break;
                case HASHTABLE_BUFFER:
                    log_printf ("      key (buffer) . . . : %p", ptr_item->key);
                    break;
                case HASHTABLE_TIME:
                    log_printf ("      key (time) . . . . : %lld", (long long)(*((time_t *)ptr_item->key)));
                    break;
                case HASHTABLE_LONGLONG:
                    log_printf ("      key (long long). . : %lld", *((long long *)ptr_item->key));
                    break;
                case HASHTABLE_NUM_TYPES:
                    break;
            }
            log_printf ("      key_size . . . . . : %d", ptr_item->key_size);
            switch (hashtable->type_values)
            {
                case HASHTABLE_INTEGER:
                    log_printf ("      value (integer). . : %d", *((int *)ptr_item->value));
                    break;
                case HASHTABLE_STRING:
                    log_printf ("      value (string) . . : '%s'", (char *)ptr_item->value);
                    break;
                case HASHTABLE_POINTER:
                    log_printf ("      value (pointer). . : %p", ptr_item->value);
                    break;
                case HASHTABLE_BUFFER:
                    log_printf ("      value (buffer) . . : %p", ptr_item->value);
                    break;
                case HASHTABLE_TIME:
                    log_printf ("      value (time) . . . : %lld", (long long)(*((time_t *)ptr_item->value)));
                    break;
                case HASHTABLE_LONGLONG:
                    log_printf ("      value (long long). : %lld", *((long long *)ptr_item->value));
                    break;
                case HASHTABLE_NUM_TYPES:
                    break;
            }
            log_printf ("      value_size . . . . : %d", ptr_item->value_size);
            log_printf ("      prev_item. . . . . : %p", ptr_item->prev_item);
            log_printf ("      next_item. . . . . : %p", ptr_item->next_item);
            log_printf ("      prev_created_item. : %p", ptr_item->prev_created_item);
            log_printf ("      next_created_item. : %p", ptr_item->next_created_item);
        }
    }
}
